The sports universe was abuzz Thursday with speculation regarding when wide receiver Vincent Jackson will report to the Chargers.

Initial reports had him coming in by Oct. 31, the day of the Chargers’ eighth game.

Hopefully for Jackson’s sake, it’s before that, or he won’t get the accrued season that is apparently his main reason for joining the Chargers this season.

Team Jackson certainly knows the receiver must report by 1 p.m. PT on Oct. 30 in order to sit out his three games on the Roster Exempt List and still get his six games on the roster in order to be a free man.

(More on timing later.)

An ESPN report, citing sources, says that upon advice from the NFL Players Association both Jackson and New England Patriots guard Logan Mankins will report in time to spend six games on their respective team’s roster and become unrestricted free agents after the season.

This was always a possibility.

The Chargers felt all along the rules were on their side – that Jackson would be a restricted free agent again if he did not report in 2010. Therefore, the team quietly harbored a belief that Jackson would sign in time to get his six games on the roster and become an unrestricted free agent after this season.

But this turn of events is still surprising for the fact that Jackson said in his one interview and his agents said vehemently, again and again, that he would not play for the Chargers this season for the team’s one-year tender offer.

Once Jackson made the decision to not play for the one-year $3.268 million tender, that stance was at least understandable. If not willing to do so for more than three mil, why play for the $583,000 the tender was cut to on June 15. And then Jackson was put on the Roster Exempt List in August, meaning he had to sit out three games following his signing and reporting.

Having taken a $34,000 pay loss for every game missed, Jackson will make just shy of $206,000 should he report on Oct. 30 and join the roster before the Chargers’ Nov. 28 game at Indianapolis.

Union general counsel Richard Berthelsen did not respond to a request for comment on the NFLPA’s take.

Asked Thursday to speak to the possibility Jackson will report to the Chargers this season, agent Neil Schwartz said, “I have no comment.”

That’s in sharp contrast to Schwartz’s and partner Jonathan Feinsod’s inability to not have a comment in August and September.

On Sept. 22, the day the Chargers declined the Minnesota Vikings’ final trade offer and sent Schwartz and Feinsod on a media rampage, Schwartz was asked, just to be sure, whether Jackson would play for the Chargers this season.

“Vincent will not play for the Chargers,” Schwartz replied.

But now, evidently, he will.

If so, the remaining question will be how will he play?

The questions that have been asked – and then set aside – in the hallways, offices and meeting rooms at Chargers Park is whether Jackson will make the best of a bad situation.

Teammates and coaches believe he will perform at a level commensurate with his work the past two seasons — when he ranked second in receiving average, tied for sixth in receiving touchdowns and 11th in receiving yards.

While he won’t get a long-term deal in San Diego, as McNeill did this week, Jackson can show in six weeks (plus playoffs?) he is worth what he’s been asking.

Jackson is an amazing athlete who is always in fantastic shape. He has had hamstring issues, but the three weeks on Roster Exempt Status should allow him to get into football shape.

As long as he knows he has to be here by Oct. 30. Signed, sealed and delivered by 1 p.m.

Easy, right?

Well, remember the Sept. 4 deadline for Jackson to reach a contract agreement with another team and have a trade consummated so he could serve his DUI suspension and Roster Exempt time concurrently? That was the first time Jackson’s agents said the Chargers stymied a trade.

Turns out, the chance the Chargers had to make a deal was actually no chance at all.

A source said Thursday that the Chargers did not even get the call from the Minnesota Vikings informing them the Vikings had reached a deal with Jackson until 3:01 p.m. PT. A deadline for a deal to be done required Jackson’s signed tender and a trade agreement to be received by the league by 3 p.m.

Whether the Chargers and Vikings could have worked something out that day is not known – though perhaps the Vikings would have been willing to offer slightly more than they were 2½ weeks later if they could have had Jackson for an extra game.